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Diffstat (limited to 'butl/process')
| -rw-r--r-- | butl/process | 569 |
1 files changed, 0 insertions, 569 deletions
diff --git a/butl/process b/butl/process deleted file mode 100644 index 9c0d060..0000000 --- a/butl/process +++ /dev/null @@ -1,569 +0,0 @@ -// file : butl/process -*- C++ -*- -// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd -// license : MIT; see accompanying LICENSE file - -#ifndef BUTL_PROCESS -#define BUTL_PROCESS - -#ifndef _WIN32 -# include <sys/types.h> // pid_t -#endif - -#include <vector> -#include <iosfwd> -#include <cassert> -#include <cstdint> // uint32_t -#include <system_error> - -#include <butl/path> -#include <butl/export> -#include <butl/optional> -#include <butl/fdstream> // auto_fd, fdpipe -#include <butl/vector-view> -#include <butl/small-vector> - -namespace butl -{ - struct process_error: std::system_error - { - const bool child; - - process_error (int e, bool child = false) - : system_error (e, std::generic_category ()), child (child) {} - -#ifdef _WIN32 - process_error (const std::string& d, int fallback_errno_code = 0) - : system_error (fallback_errno_code, std::system_category (), d), - child (false) {} -#endif - }; - - struct process_child_error: process_error - { - explicit - process_child_error (int e): process_error (e, true) {} - }; - - // Process arguments (i.e., the command line). The first must be an - // executable name and the last element should be NULL. Can also be the - // multi-process piped command line (see process::print() for details). - // - struct process_args - { - const char* const* argv; - std::size_t argc; - }; - - // A process executable has three paths: initial, recall, and effective. - // Initial is the original "command" that you specify in argv[0] and on - // POSIX that's what ends up in the child's argv[0]. But not on Windows. On - // Windows the command is first searched for in the parent executable's - // directory and if found then that's what should end up in child's argv[0]. - // So this is the recall path. It is called recall because this is what the - // caller of the parent process will be able to execute if you printed the - // command line (provided you haven't changed the CWD). Finally, effective - // is the absolute path to the executable that will include the directory - // part if found in PATH, the .exe extension if one is missing, etc. - // - // As an example, let's say we run foo\foo.exe that itself spawns bar which - // is found as foo\bar.exe. The paths will then be: - // - // initial: bar - // recall: foo\bar - // effective: c:\...\foo\bar.exe - // - // In most cases, at least on POSIX, the first two paths will be the same. - // As an optimization, if the recall path is empty, then it means it is the - // same as initial. Similarly, if the effective path is empty then, it is - // the same as recall (and if that is empty, as initial). - // - // Note that the call to path_search() below adjust args[0] to point to the - // recall path which brings up lifetime issues. To address this this class - // also implements an RAII-based auto-restore of args[0] to its initial - // value. - // - class process_path - { - public: - const char* initial = nullptr; - path recall; - path effect; - - // Handle empty recall/effect. - // - const char* recall_string () const; - const char* effect_string () const; - - bool empty () const - { - return initial == nullptr && recall.empty () && effect.empty (); - } - - // Moveable-only type. - // - process_path (process_path&&); - process_path& operator= (process_path&&); - - process_path (const process_path&) = delete; - process_path& operator= (const process_path&) = delete; - - process_path () = default; - process_path (const char* i, path&& r, path&& e); - ~process_path (); - - private: - friend class process; - const char** args0_ = nullptr; - }; - - // Process exit information. - // - struct LIBBUTL_EXPORT process_exit - { - // Status type is the raw exit value as returned by GetExitCodeProcess() - // (NTSTATUS value that represents exit or error codes; MSDN refers to the - // error code as "value of the exception that caused the termination") or - // waitpid(1). Code type is the return value if the process exited - // normally. - // -#ifndef _WIN32 - using status_type = int; - using code_type = std::uint8_t; -#else - using status_type = std::uint32_t; // Win32 DWORD - using code_type = std::uint16_t; // Win32 WORD -#endif - - status_type status; - - process_exit () = default; - - explicit - process_exit (code_type); - - enum as_status_type {as_status}; - process_exit (status_type s, as_status_type): status (s) {} - - // Return false if the process exited abnormally. - // - bool - normal () const; - - code_type - code () const; - - explicit operator bool () const {return normal () && code () == 0;} - - // Abnormal termination information. - // - - // Return the signal number that caused the termination or 0 if no such - // information is available. - // - int - signal () const; - - // Return true if the core file was generated. - // - bool - core () const; - - // Return a description of the reason that caused the process to terminate - // abnormally. On POSIX this is the signal name, on Windows -- the summary - // produced from the corresponding error identifier defined in ntstatus.h. - // - std::string - description () const; - }; - - class LIBBUTL_EXPORT process - { - public: -#ifndef _WIN32 - using handle_type = pid_t; - using id_type = pid_t; -#else - using handle_type = void*; // Win32 HANDLE - using id_type = std::uint32_t; // Win32 DWORD -#endif - - // Start another process using the specified command line. The default - // values to the in, out and err arguments indicate that the child process - // should inherit the parent process stdin, stdout, and stderr, - // respectively. If -1 is passed instead, then the corresponding child - // process descriptor is connected (via a pipe) to out_fd for stdin, - // in_ofd for stdout, and in_efd for stderr (see data members below). If - // -2 is passed, then the corresponding child process descriptor is - // replaced with the null device descriptor (e.g., /dev/null). This - // results in the child process not being able to read anything from stdin - // (gets immediate EOF) and all data written to stdout/stderr being - // discarded. - // - // On Windows parent process pipe descriptors are set to text mode to be - // consistent with the default (text) mode of standard file descriptors of - // the child process. When reading in the text mode the sequence of 0xD, - // 0xA characters is translated into the single OxA character and 0x1A is - // interpreted as EOF. When writing in the text mode the OxA character is - // translated into the 0xD, 0xA sequence. Use the fdmode() function to - // change the mode, if required. - // - // Instead of passing -1, -2 or the default value, you can also pass your - // own descriptors. Note, however, that in this case they are not closed by - // the parent. So you should do this yourself, if required. For example, - // to redirect the child process stdout to stderr, you can do: - // - // process p (..., 0, 2); - // - // Throw process_error if anything goes wrong. Note that some of the - // exceptions (e.g., if exec() failed) can be thrown in the child - // version of us (as process_child_error). - // - // Note that the versions without the the process_path argument may - // temporarily change args[0] (see path_search() for details). - // - process (const char* args[], int in = 0, int out = 1, int err = 2); - - process (const process_path&, const char* args[], - int in = 0, int out = 1, int err = 2); - - // The "piping" constructor, for example: - // - // process lhs (..., 0, -1); // Redirect stdout to a pipe. - // process rhs (..., lhs); // Redirect stdin to lhs's pipe. - // - // rhs.wait (); // Wait for last first. - // lhs.wait (); - // - process (const char* args[], process& in, int out = 1, int err = 2); - - process (const process_path&, const char* args[], - process& in, int out = 1, int err = 2); - - // Versions of the above constructors that allow us to change the - // current working directory of the child process. NULL and empty - // cwd arguments are ignored. - // - process (const char* cwd, const char* [], int = 0, int = 1, int = 2); - - process (const char* cwd, - const process_path&, const char* [], - int = 0, int = 1, int = 2); - - process (const char* cwd, const char* [], process&, int = 1, int = 2); - - process (const char* cwd, - const process_path&, const char* [], - process&, int = 1, int = 2); - - // Wait for the process to terminate. Return true if the process - // terminated normally and with the zero exit code. Unless ignore_error - // is true, throw process_error if anything goes wrong. This function can - // be called multiple times with subsequent calls simply returning the - // status. - // - bool - wait (bool ignore_errors = false); - - // Return true if the process has already terminated in which case - // optionally set the argument to the result of wait(). - // - bool - try_wait (); - - bool - try_wait (bool&); - - // Note that the destructor will wait for the process but will ignore - // any errors and the exit status. - // - ~process () {if (handle != 0) wait (true);} - - // Moveable-only type. - // - process (process&&); - process& operator= (process&&); - - process (const process&) = delete; - process& operator= (const process&) = delete; - - // Create an empty or "already terminated" process. By default the - // termination status is unknown but you can change that. - // - explicit - process (optional<process_exit> = nullopt); - - // Resolve process' paths based on the initial path in args0. If recall - // differs from initial, adjust args0 to point to the recall path. If - // resolution fails, throw process_error. Normally, you will use this - // function like this: - // - // const char* args[] = {"foo", ..., nullptr}; - // - // process_path pp (process::path_search (args[0])) - // - // ... // E.g., print args[0]. - // - // process p (pp, args); - // - // You can also specify the fallback directory which will be tried last. - // This, for example, can be used to implement the Windows "search in the - // parent executable's directory" semantics across platforms. - // - static process_path - path_search (const char*& args0, const dir_path& fallback = dir_path ()); - - // This version is primarily useful when you want to pre-search the - // executable before creating the args[] array. In this case you will - // use the recall path for args[0]. - // - // The init argument determines whether to initialize the initial path to - // the shallow copy of file. If it is true, then initial is the same as - // file and recall is either empty or contain a different path. If it is - // false then initial contains a shallow copy of recall, and recall is - // either a different path or a deep copy of file. Normally you don't care - // about initial once you got recall and the main reason to pass true to - // this argument is to save a copy (since initial and recall are usually - // the same). - // - static process_path - path_search (const char* file, bool init, const dir_path& = dir_path ()); - - static process_path - path_search (const std::string&, bool, const dir_path& = dir_path ()); - - static process_path - path_search (const path&, bool, const dir_path& = dir_path ()); - - // As above but if not found return empty process_path instead of - // throwing. - // - static process_path - try_path_search (const char*, bool, const dir_path& = dir_path ()); - - static process_path - try_path_search (const std::string&, bool, const dir_path& = dir_path ()); - - static process_path - try_path_search (const path&, bool, const dir_path& = dir_path ()); - - // Print process commmand line. If the number of elements is specified, - // then it will print the piped multi-process command line, if present. - // In this case, the expected format is as follows: - // - // name1 arg arg ... nullptr - // name2 arg arg ... nullptr - // ... - // nameN arg arg ... nullptr nullptr - // - static void - print (std::ostream&, const char* const args[], size_t n = 0); - - public: - id_type - id () const; - - static id_type - current_id (); - - public: - handle_type handle; - - // Absence means that the exit information is not (yet) known. This can be - // because you haven't called wait() yet or because wait() failed. - // - optional<process_exit> exit; - - // Use the following file descriptors to communicate with the new process's - // standard streams. - // - auto_fd out_fd; // Write to it to send to stdin. - auto_fd in_ofd; // Read from it to receive from stdout. - auto_fd in_efd; // Read from it to receive from stderr. - }; - - // Higher-level process running interface that aims to make executing a - // process for the common cases as simple as calling a functions. Normally - // it is further simplified by project-specific wrapper functions that - // handle the process_error exception as well as abnormal and/or non-zero - // exit status. - // - // The I/O/E arguments determine the child's stdin/stdout/stderr. They can - // be of type int, auto_fd (and, in the future, perhaps also fd_pipe, - // string, buffer, etc). For example, the following call will make stdin - // read from /dev/null, stdout redirect to stderr, and inherit the parent's - // stderr. - // - // process_run (..., fdnull (), 2, 2, ...) - // - // The P argument is the program path. It can be anything that can be passed - // to process::path_search() (const char*, std::string, path) or the - // process_path itself. - // - // The A arguments can be anything convertible to const char* via the - // overloaded process_arg_as() (see below). Out of the box you can use const - // char*, std::string, path/dir_path, (as well as [small_]vector[_view] of - // these), and numeric types. - // - template <typename I, - typename O, - typename E, - typename P, - typename... A> - process_exit - process_run (I&& in, - O&& out, - E&& err, - const dir_path& cwd, - const P&, - A&&... args); - - // The version with the command callback that can be used for printing the - // command line or similar. It should be callable with the following - // signature: - // - // void (const char*[], std::size_t) - // - template <typename C, - typename I, - typename O, - typename E, - typename P, - typename... A> - process_exit - process_run (const C&, - I&& in, - O&& out, - E&& err, - const dir_path& cwd, - const P&, - A&&... args); - - // Versions that start the process without waiting. - // - template <typename I, - typename O, - typename E, - typename P, - typename... A> - process - process_start (I&& in, - O&& out, - E&& err, - const dir_path& cwd, - const P&, - A&&... args); - - template <typename C, - typename I, - typename O, - typename E, - typename P, - typename... A> - process - process_start (const C&, - I&& in, - O&& out, - E&& err, - const dir_path& cwd, - const P&, - A&&... args); - - // Conversion of types to their C string representations. Can be overloaded - // (including via ADL) for custom types. The default implementation calls - // to_string() which covers all the numeric values via std::to_string () and - // also any type that defines to_string() (via ADL). - // - template <typename T> - inline const char* - process_arg_as (const T& x, std::string& storage) - { - using namespace std; - return (storage = to_string (x)).c_str (); - } - - inline const char* - process_arg_as (const std::string& s, std::string&) {return s.c_str ();} - - template <typename K> - inline const char* - process_arg_as (const basic_path<char, K>& p, std::string&) - { - return p.string ().c_str (); - } - - // char[N] - // - inline const char* - process_arg_as (const char* s, std::string&) {return s;} - - template <std::size_t N> - inline const char* - process_arg_as (char (&s)[N], std::string&) {return s;} - - template <std::size_t N> - inline const char* - process_arg_as (const char (&s)[N], std::string&) {return s;} - - template <typename V, typename T> - inline void - process_args_as (V& v, const T& x, std::string& storage) - { - v.push_back (process_arg_as (x, storage)); - } - - // [small_]vector[_view]<> - // - template <typename V> - inline void - process_args_as (V& v, const std::vector<std::string>& vs, std::string&) - { - for (const std::string& s: vs) - v.push_back (s.c_str ()); - } - - template <typename V, std::size_t N> - inline void - process_args_as (V& v, const small_vector<std::string, N>& vs, std::string&) - { - for (const std::string& s: vs) - v.push_back (s.c_str ()); - } - - template <typename V> - inline void - process_args_as (V& v, const vector_view<std::string>& vs, std::string&) - { - for (const std::string& s: vs) - v.push_back (s.c_str ()); - } - - template <typename V> - inline void - process_args_as (V& v, const std::vector<const char*>& vs, std::string&) - { - for (const char* s: vs) - v.push_back (s); - } - - template <typename V, std::size_t N> - inline void - process_args_as (V& v, const small_vector<const char*, N>& vs, std::string&) - { - for (const char* s: vs) - v.push_back (s); - } - - template <typename V> - inline void - process_args_as (V& v, const vector_view<const char*>& vs, std::string&) - { - for (const char* s: vs) - v.push_back (s); - } -} - -#include <butl/process.ixx> - -#include <butl/process-run.txx> - -#endif // BUTL_PROCESS |